Q represents the yield limit of this material, and the latter 235 refers to the yield value of this material, which is about 235MPa. The yield value will decrease with the increase of material thickness. Because of moderate carbon content, good comprehensive properties and good matching of strength, plasticity and weldability, it is the most widely used.
Extended data:
Use of Q235:
1, widely used in buildings and engineering structures. Used for manufacturing steel bars or building factories, high-voltage transmission towers, bridges, vehicles, boilers, containers, ships, etc. It is also widely used as mechanical parts with low performance requirements. Grade C and D steels can also be used for some professional steels.
2. It can be used for various unimportant mold parts such as mold handles.
3. The punch is made of Q235 steel, which can be used directly without tempering after quenching, and the hardness is 36~40HRC, which solves the fracture phenomenon of the punch in use.
1 and hardness of a3 steel: HRC40-44.
2. Hardness after quenching: low carbon steel [Q235 (new standard, equivalent to original A3 steel), 15#, 20#]: solid carburizing quenching, carburizing depth is generally 0.8~ 1.2mm (0.3~0.5mm when hammer thickness is 2mm), and surface hardness is generally HRC56~62.
3. Hardness unit: the hardness code of steel is H. According to different hardness test methods, there are Brinell (HB), Rockwell (HRC), Vickers (HV) and Richter scale (HL) hardness, among which HB and HRC are commonly used.
Baidu encyclopedia -Q235
Baidu encyclopedia -A3 steel